TY - JOUR

T1 - Food Webs and Fish Size Patterns in Insular Lakes Partially Support Climate-Related Features in Continental Lakes

AU - Vidal, Nicolas

AU - Amsinck, Susanne L.

AU - Gonçalves, Vítor

AU - Neto Azevedo, José M.

AU - Johansson, Liselotte S.

AU - Christoffersen, Kirsten S.

AU - Lauridsen, Torben L.

AU - Søndergaard, Martin

AU - Bjerring, Rikke

AU - Landkildehus, Frank

AU - Brodersen, Klaus P.

AU - Meerhoff, Mariana

AU - Jeppesen, Erik

N1 - Funding Information: This research was funded by the Carlsberg Foundation, Research Council of Nature and Universe (272-08-0406), the TK Foundation, Dronning Margrethes og Prins Henriks Fond, Torben and Alice Frimodts Fond, Christian og Ottila Brorsons Rejselegat, Sino-Danish Centre for Education and Research, Aarhus University, University of Copenhagen, the Danish project CRES, and the EU project MARS (Managing Aquatic ecosystems and water Resources under multiple Stress) funded under the 7th EU Framework Programme, Theme 6 (Environment including Climate Change), Contract No.: 603378 (http://www.mars-project.eu). This is a contribution from the Galathea 3 expedition. MM is supported by SNI-ANII Uruguay and the L?Or?al-UNESCO national award for Women in Science and EJ by the T?BITAK, BIDEB 2232 program (118C250). Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2021

Y1 - 2021

N2 - Disentangling the effects of climate change on nature is one of the main challenges facing ecologists nowadays. Warmer climates forces strong effects on lake biota for fish, leading to a reduction in size, changes in diet, more frequent reproduction, and stronger cascading effects. Spacefor-time substitution studies (SFTS) are often used to unravel climate effects on lakes biota; however, results from continental lakes are potentially confounded by biogeographical and evolutionary differences, also leading to an overall higher fish species richness in warm lakes. Such differences may not be found in lakes on remote islands, where natural fish free lakes have been subjected to stocking only during the past few hundred years. We studied 20 species-poor lakes located in two remote island groups with contrasting climates, but similar seasonality: the Faroe Islands (cold; 6.5 ± 2.8 °C annual average (SD) and the Azores Islands (warm; 17.3 ± 2.9 °C)). As for mainland lakes, mean body size of fish in the warmer lakes were smaller overall, and phytoplankton per unit of phosphorus higher. The δ13C carbon range for basal organisms, and for the whole food web, appeared wider in colder lakes. In contrast to previous works in continental fresh waters, Layman metrics of the fish food web were similar between the two climatic regions. Our results from insular systems provide further evidence that ambient temperatures, at least partially, drive the changes in fish size structure and the cascading effects found along latitude gradients in lakes.

AB - Disentangling the effects of climate change on nature is one of the main challenges facing ecologists nowadays. Warmer climates forces strong effects on lake biota for fish, leading to a reduction in size, changes in diet, more frequent reproduction, and stronger cascading effects. Spacefor-time substitution studies (SFTS) are often used to unravel climate effects on lakes biota; however, results from continental lakes are potentially confounded by biogeographical and evolutionary differences, also leading to an overall higher fish species richness in warm lakes. Such differences may not be found in lakes on remote islands, where natural fish free lakes have been subjected to stocking only during the past few hundred years. We studied 20 species-poor lakes located in two remote island groups with contrasting climates, but similar seasonality: the Faroe Islands (cold; 6.5 ± 2.8 °C annual average (SD) and the Azores Islands (warm; 17.3 ± 2.9 °C)). As for mainland lakes, mean body size of fish in the warmer lakes were smaller overall, and phytoplankton per unit of phosphorus higher. The δ13C carbon range for basal organisms, and for the whole food web, appeared wider in colder lakes. In contrast to previous works in continental fresh waters, Layman metrics of the fish food web were similar between the two climatic regions. Our results from insular systems provide further evidence that ambient temperatures, at least partially, drive the changes in fish size structure and the cascading effects found along latitude gradients in lakes.

KW - Climate change

KW - Islands

KW - Space-for-time substitution

KW - Stable isotopes

U2 - 10.3390/w13101380

DO - 10.3390/w13101380

M3 - Journal article

AN - SCOPUS:85106647905

VL - 13

JO - Water

JF - Water

SN - 2073-4441

IS - 10

M1 - 1380

ER -